Can a Gmail filter act on email size?

Last reviewed: October 29, 2026 · Markdown version

Yes. Size is one of the fields in Gmail's search options, and a filter in Gmail is built from a search, so a size rule is a size search with an action attached. The steps take about a minute on a computer.

Making the filter

In Gmail on a computer, click Show search options in the search box.
Fill in Size, which Google describes as "Searches for emails that match a certain size" (Search in Gmail, read 29 October 2026). Add anything else you want to match, such as a sender.
Click Search to check the results look right, then "At the bottom of the search window, click Create filter" (Create rules to filter your emails, read 29 October 2026).
Choose the action. Google's list is to "send email to a label, or archive, delete, star, or automatically forward your mail".

Typing the size into the search box works just as well. Gmail's operator reference groups three operators under "Find emails by their size": size:, larger: and smaller:, with size:1000000 and larger:10M as its examples (Refine searches in Gmail, read 29 October 2026). The same page notes that "you can use the results to set up a filter for these messages".

Email size, not attachment size

Both Google pages talk about the size of the email. Neither describes a way to test one attachment's size on its own, so a filter catches the whole message as it is measured, body and attachments together as we read it. To aim at heavy attachments in particular, pair the size with has:attachment, an operator on the same reference page: has:attachment larger:10M.

What Google's filter page leaves open

The filter page says one thing about timing, and only for forwarding: "When you create a filter to forward messages, only new messages will be affected" (the Create rules to filter your emails page above). It does not say whether the other actions reach mail already in your account. Plan for a size filter to handle what arrives from now on, and deal with the existing heavy mail from the search results themselves; finding large emails walks through that clear-out.

It also says nothing about the order filters run in when a large message matches two of them. If a size filter and a sender filter could both fire, give them actions that do not fight, such as two labels.

A size rule that is safe to leave running

Our suggestion is to have a size filter label rather than delete. A rule such as larger:15M that applies a label called "Large" costs nothing, and the label becomes the list you check when storage gets tight. A delete action would also bin the one large message you needed, a scanned contract or a set of photos, without asking. For the attachment ceiling the other way round, what Gmail lets you send, see Gmail's attachment limit.